JP7127931B2 - Diffraction light guide plate and method for manufacturing diffraction light guide plate - Google Patents

Description

This specification claims the benefit of the filing date of Korean Patent Application No. 10-2017-0138685 filed with the Korean Intellectual Property Office on October 24, 2017, the entire contents of which are incorporated into the present invention.

The present invention relates to a diffractive light guide plate and a method for manufacturing the diffractive light guide plate.

Recently, as interest in display units that realize augmented reality (AR), mixed reality (MR), or virtual reality (VR) has increased, research has been conducted on display units that realize this. It tends to be active. A display unit that realizes augmented reality, mixed reality, or virtual reality is equipped with a diffractive light guide plate that utilizes the diffraction phenomenon based on the wave-dynamic properties of light. Such a diffractive light guide plate basically comprises three substrates overlaid with a patterned layer containing lattice-like nanopatterns capable of diffracting light. However, the diffractive light guide plate with three substrates is thick and has a rather heavy problem in realizing weight reduction of the display unit that realizes augmented reality, mixed reality, or virtual reality.

In addition, when the pattern layer is formed on one surface of the substrate, the substrate may be deformed due to the stress of the pattern layer. A display unit using a diffractive light guide plate including a base material deformed by the stress of the pattern layer may have a problem that the display performance is remarkably deteriorated.

Accordingly, there is a need for a technology that can effectively reduce the thickness and weight of the diffraction light guide plate and a technology that can prevent the substrate constituting the diffraction light guide plate from being deformed by the stress of the pattern layer. This is the current situation.

The present specification seeks to provide a diffractive light guide plate and a method for manufacturing the diffractive light guide plate.

However, the problems to be solved by the present invention are not limited to the above problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

One embodiment of the present invention includes a first diffractive substrate and a second diffractive substrate provided on the first diffractive substrate, the first diffractive substrate having a first diffraction grating layer on one side. and a second grating layer on one side, the second grating layer comprising a third grating layer on one side and a stress compensation layer on the other side, the first grating layer comprising: The second diffraction grating layer separates light with a wavelength of 400 nm or more and 550 nm or less, and the third diffraction grating layer separates light with a wavelength of 450 nm or more and 650 nm or less. and the stress compensation layer has a stress in the same direction as the stress of the third diffraction grating layer.

An embodiment of the present invention also provides a method of manufacturing a diffractive light guide plate. Specifically, one embodiment of the present invention comprises the steps of providing a first diffractive substrate comprising a first grating layer on one side and a second grating layer on the other side; providing a second diffractive substrate including a grating layer and a stress compensation layer on the other side; and bonding the first diffractive substrate and the second diffractive substrate. A method for manufacturing a light plate is provided.

According to one embodiment of the present invention, the diffraction light guide plate includes a first diffraction base material having a first diffraction grating layer on one surface and a second diffraction grating layer on the other surface, so that the diffraction light guide plate thickness and weight can be effectively reduced.

According to one embodiment of the present invention, by forming a stress compensating layer on the other side of the second diffractive substrate including the third grating layer on one side, the stress that can be caused by the stress of the third grating layer Deformation of the second diffraction base material can be effectively suppressed.

According to one embodiment of the present invention, it is possible to easily manufacture a diffractive light guide plate with reduced thickness and weight.

FIG. 4 is a diagram schematically showing that a substrate is deformed by forming a patterned layer on one surface of the substrate; FIG. 4 is a diagram schematically showing that a substrate is deformed by forming a patterned layer on one surface of the substrate; Fig. 2 schematically shows a diffractive light guide plate comprising three substrates with a patterned layer formed on one side thereof; It is a figure which shows roughly the diffraction light-guide plate which concerns on one embodiment of this invention. It is a figure which shows roughly the diffraction light-guide plate which concerns on one embodiment of this invention. It is a figure which shows roughly the diffraction light-guide plate which concerns on one embodiment of this invention. It is a figure which shows roughly the diffraction light-guide plate which concerns on one embodiment of this invention. The in-coupling angle and the out-coupling angle of the first diffraction substrate provided with the first diffraction grating layer and the second diffraction grating layer according to one embodiment of the present invention coupling angle). FIG. 4 shows in-coupling angles and out-coupling angles of a diffraction substrate having a first diffraction grating layer and a third diffraction grating layer; FIG. FIG. 3B is a diagram schematically showing a plane of a first diffraction grating layer according to an embodiment of the present invention; FIG. 4 is a diagram schematically showing a cross-section of a first diffraction substrate including a first diffraction grating layer according to one embodiment of the present invention; Fig. 3 schematically illustrates a first grating layer including a diffraction pattern according to one embodiment of the present invention; FIG. 4B is a diagram schematically showing a cross-section of a diffraction pattern included in a first diffraction grating layer according to one embodiment of the present invention; 6 shows simulation results of the optical diffraction efficiency of the diffraction grating layer according to the duty, height, and optical refractive index of pattern structures included in the diffraction grating layer according to one embodiment of the present invention. FIG. 4 is a diagram schematically showing a cross section of a diffraction light guide plate including first to third diffraction grating layers according to one embodiment of the present invention; FIG. 4 is a diagram schematically showing a cross section of a diffraction light guide plate including first to third diffraction grating layers according to one embodiment of the present invention; FIG. 2 schematically illustrates a first diffraction grating layer including first to third diffraction patterns according to one embodiment of the present invention; FIG. 2 schematically illustrates preparing a first diffractive substrate using two substrates according to an embodiment of the invention; 1 is a scanning electron microscope (SEM) photograph of a first diffraction grating layer according to Example 1 of the present invention; 4 is a scanning electron microscope (SEM) photograph of a second diffraction grating layer according to Example 1 of the present invention; 4 is a scanning electron microscope (SEM) photograph of a third diffraction grating layer according to Example 1 of the present invention; 1 is a scanning electron microscope (SEM) photograph of a stress compensation layer including an antireflection pattern according to Example 1 of the present invention; 4 is a graph showing the results of measuring the light transmittance of the second diffractive substrate prepared in Example 1 of the present invention and the substrates prepared in Reference Examples 1 to 5. FIG. 2 is a graph showing the results of measuring the light transmittance of the second diffractive base prepared in Example 2 of the present invention and the bases prepared in Reference Examples 6 and 7. FIG. FIG. 10 is a diagram showing a 3D image of a substrate in the process of manufacturing the substrate in Reference Example 8; FIG. 10 is a diagram showing a 3D image of a substrate in the process of manufacturing the substrate in Reference Example 9;

Throughout the specification, when a part "includes" a component, it means that it can further include other components, rather than excluding other components, unless specifically stated to the contrary. do.

In this specification, when a member is positioned “above” another member, this includes not only the case where the member is in contact with the other member, but also the case where the other member is between the two members. This includes the case where there is a member of

Throughout the specification, when a part is "connected" to another part, it means "directly connected" as well as "with another element in between". Including cases where they are linked.

In this specification, the thickness of a certain member can be the average value of arbitrary 10 measurement values obtained by observing the cross section of the member with an electron microscope (SEM, TEM, STEM). When the thickness of the member is very thin, it can be measured by enlarging a photograph observed at a high magnification. can be measured.

The present inventors formed a first diffraction grating layer on one surface of a first diffraction substrate and formed a second diffraction grating layer on the other surface of the first diffraction substrate to manufacture a diffraction light guide plate It has been found that the overall thickness and weight of the can be effectively reduced. Further, a first diffraction grating layer capable of separating a first light having a wavelength value of 550 nm or more and 700 nm or less is included on one surface, and a second diffraction grating layer capable of separating a second light having a wavelength value of 400 nm or more and 550 nm or less. on the other side can effectively prevent cross talk that can occur between the first light and the second light. Further, a third diffraction grating layer is formed on one surface of the second diffraction base, and a stress compensation layer is formed on the other surface of the second diffraction base, so that the stress of the third diffraction grating layer causes the second diffraction base to expand. After clarifying that the material can be prevented from being deformed, the following diffractive light guide plate and its manufacturing method were developed.

The present specification will be described in more detail below.

One embodiment of the present invention includes a first diffractive substrate and a second diffractive substrate provided on the first diffractive substrate, the first diffractive substrate having a first diffraction grating layer on one side. and a second grating layer on one side, the second grating layer comprising a third grating layer on one side and a stress compensation layer on the other side, the first grating layer comprising: The second diffraction grating layer separates light with a wavelength of 400 nm or more and 550 nm or less, and the third diffraction grating layer separates light with a wavelength of 450 nm or more and 650 nm or less. and the stress compensation layer has a stress in the same direction as the stress of the third diffraction grating layer.

According to one embodiment of the present invention, the diffraction light guide plate includes a first diffraction base material having a first diffraction grating layer on one surface and a second diffraction grating layer on the other surface, so that the diffraction light guide plate thickness and weight can be effectively reduced.

In addition, according to an embodiment of the present invention, by forming a stress compensation layer on the other surface of the second diffraction base including the third diffraction grating layer on one surface, the stress generated by the stress of the third diffraction grating layer is formed. Possible deformation of the second diffraction base material can be effectively suppressed.

A display unit that realizes augmented reality (AR), mixed reality (MR), or virtual reality (VR) includes a diffraction light guide plate that utilizes a diffraction phenomenon based on the wave dynamic properties of light. I have. A conventional diffractive light guide plate basically comprises three substrates for diffracting light, and each of the three substrates is formed with a pattern layer containing a grating pattern on one side. However, the conventional diffractive light guide plate, which includes three substrates each having a patterned layer formed on one surface thereof, is thick and has a heavy problem. In addition, a base material having a pattern layer formed only on one side may have a problem that the base material is deformed due to the stress of the pattern layer.

FIGS. 1A and 1B are diagrams schematically showing deformation of a base layer by forming a pattern layer on one surface of the base layer. Specifically, FIG. 1A is a diagram showing that the base material layer 10 provided with the pattern layer 20 is deformed due to the occurrence of compressive stress in the pattern layer 20 formed on one surface of the base material layer 10 . is. FIG. 1B is a diagram showing that the substrate layer 10 provided with the pattern layer 20 is deformed due to the tensile stress generated in the pattern layer 20 formed on one surface of the substrate layer 10 . The grid pattern included in the pattern layer 20 is omitted in FIGS. 1A and 1B.

Compressive stress or tensile stress is generated in the pattern layer formed on one side of the base layer due to various factors such as materials of the pattern layer and the base layer, process conditions for forming the pattern layer on the base layer, etc. There is As an example, after applying the composition for forming the pattern layer onto the substrate layer, the thermal stress generated during the step of drying the composition and/or the step of curing the composition, or the substrate A compressive or tensile stress is created in the pattern layer, such as by the shrinkage behavior of the composition applied onto the material layer. As shown in FIGS. 1A and 1B, the compressive stress or tensile stress generated in the pattern layer 20 may deform the base layer 10 .

FIG. 2 is a schematic diagram of a diffractive light guide plate comprising three substrate layers with patterned layers formed on one surface thereof. Specifically, FIG. 2 shows a first substrate layer 11 having a first pattern layer 21 formed thereon, a second substrate layer 12 having a second pattern layer 22 formed thereon, and a third pattern layer 23 formed thereon. 1 is a diagram schematically showing a diffractive light guide plate including a third base layer 13 that has been laminated. FIG. Referring to FIG. 2, in the case of the base layer having the pattern layer formed only on one side, the base layer may be slightly bent due to the stress of the pattern layer. When the base layer on which the pattern layer is formed in the diffraction light guide plate is bent as shown in FIG. 2, there is a problem that the light transmittance is lowered due to the scattering of light when the light is incident on the diffraction light guide plate. As a result, the quality of the image realized by the display unit including the diffractive light guide plate may be degraded.

In contrast, according to an embodiment of the present invention, the diffraction light guide plate includes a first diffraction base material including a first diffraction grating layer on one side and a second diffraction grating layer on the other side. Therefore, the thickness and weight of the diffractive light guide plate can be effectively reduced. That is, the diffractive light guide plate includes two substrates, that is, the first diffractive substrate and the second diffractive substrate, so that the weight of the display unit including the diffractive light guide plate can be effectively reduced. Moreover, the volume of the display unit including the diffractive light guide plate can be effectively reduced.

Further, according to one embodiment of the present invention, the stress compensation layer capable of compensating or canceling the stress of the third diffraction grating layer provided on one surface of the second diffraction base is the second diffraction base. By being provided on the other side, it is possible to effectively prevent the deformation of the second diffraction substrate due to the stress of the third diffraction grating layer.

According to one embodiment of the present invention, the stress compensation layer may have stress in the same direction as the stress of the third grating layer. The stress compensation layer may have a compressive stress when a compressive stress occurs in the third diffraction grating layer, and the stress compensation layer may have a compressive stress when a tensile stress occurs in the third diffraction grating layer. It can have tensile stress. Specifically, referring to FIG. 1A, when compressive stress is generated in the third diffraction grating layer provided on one surface of the second diffraction base, tensile stress is applied to the second diffraction base. is applied. At this time, when the stress compensation layer provided on the other surface of the second diffraction base has a compressive stress in the same direction as the stress of the third diffraction grating layer, the tensile stress of the second diffraction base is It can be offset to prevent deformation of the second diffractive substrate. Also, referring to FIG. 1B, when tensile stress is generated in the third diffraction grating layer provided on one surface of the second diffraction substrate, compressive stress is applied to the second diffraction substrate. be. At this time, when the stress compensation layer provided on the other surface of the second diffraction base has tensile stress in the same direction as the stress of the third diffraction grating layer, the compressive stress of the second diffraction base is It can be offset to prevent deformation of the second diffractive substrate.

Similarly, the second diffraction grating layer included on the other surface of the first diffraction base may have stress in the same direction as the stress of the first diffraction grating layer included on one surface of the first diffraction base. can. Accordingly, it is possible to prevent deformation of the first diffraction base material due to the stress of the first diffraction grating layer.

Thus, according to one embodiment of the present invention, one side and the other side of said first diffractive substrate respectively comprise a first grating layer and a second grating layer, and The other side can be provided with a third diffraction grating layer and a stress compensation layer, respectively, to effectively prevent the first and second diffraction substrates from being deformed.

According to one embodiment of the present invention, the stress compensation layer can have a stress of 80% to 120% of the stress of the third grating layer. Specifically, the stress compensation layer is 85% to 115%, 90% to 105%, 80% to 95%, 100% to 110%, or 100% to 105% of the stress of the third grating layer. can have a stress of Also, the stress compensation layer may have the same stress as the stress of the third diffraction grating layer. By adjusting the stress ratio between the stress compensation layer and the third diffraction grating layer to fall within the range described above, it is possible to prevent the second diffraction substrate from being bent or deformed.

When the stress of the stress compensation layer is less than 80% of the stress of the third diffraction grating layer, it is difficult to effectively prevent the deformation of the second diffraction base caused by the stress of the third diffraction grating layer. be. Further, when the stress of the stress compensation layer exceeds 120% of the stress of the third diffraction grating layer, the stress of the stress compensation layer may rather cause deformation of the second diffraction base material. be.

According to one embodiment of the present invention, the stress of the stress compensation layer is controlled by adjusting the thickness of the stress compensation layer, the composition of the stress compensation layer, etc. so that the stress of the third diffraction grating layer can be compensated. can do. As an example, a stress compensation layer similar or identical in composition and thickness to the third diffraction grating layer can be provided on the other surface of the second diffraction substrate.

According to one embodiment of the present invention, the stress of the second grating layer can have a stress of 90% to 110% of the stress of the first grating layer. By adjusting the ratio of the stress of the second diffraction grating layer to the stress of the first diffraction grating layer within the range described above, deformation of the first diffraction substrate can be effectively prevented.

According to one embodiment of the present invention, a first diffraction substrate provided with a first grating layer on one side and a second grating layer on the other side, and a third grating layer on one side The extent to which the deformation of the first diffractive substrate provided with a stress compensating layer on the other side is suppressed can be measured using equipment and methods for measuring changes in film deflection in the art. . As an example, a shape change measuring device (FSM-6000LE) can be used. Also, using a 3D-coordinated measuring mechanism (3D-CMM) based on the principle of optical trigonometry, the first diffraction base material including the first diffraction grating layer and the second diffraction grating layer, and the third diffraction grating The morphology of the second diffractive substrate, including layers and stress compensating layers, can be captured in 3D images. By analyzing the captured 3D image, it is possible to confirm the extent to which the deformation of the first and second diffraction substrates is suppressed.

According to one embodiment of the present invention, the stress compensation layer may include antireflection patterns. Since the antireflection pattern is included in the stress compensation layer, it is possible to effectively suppress reflection of external light incident on the second diffraction substrate. Specifically, when a user uses a display unit that includes a second diffractive substrate on which the stress compensation layer including the antireflection pattern is provided on the other side, the antireflection pattern of the stress compensation layer is diffractive. It is possible to prevent reflection of external light other than the image information provided to the light plate. Also, the light transmittance of the second diffractive substrate including the third diffraction grating layer on one side and the stress compensation layer on the other side may be excellent.

According to one embodiment of the present invention, the anti-reflection pattern may be an anti-reflection pattern used in the industry. As an example, in the present invention, a moth-eye pattern can be formed on the surface of the stress compensation layer as an antireflection pattern.

According to one embodiment of the present invention, the optical transmittance of a second diffractive substrate, such as a second diffractive substrate provided with said third grating layer on one side and a stress compensation layer on the other side, is similar to that of a film in the art. It can be measured using an apparatus and method for measuring light transmittance such as. As an example, a light transmittance measuring device (HM-150) can be used.

According to one embodiment of the present invention, the first diffraction substrate may include a first diffraction grating layer on one side and a second diffraction grating layer on the other side, and the second diffraction substrate may include a third grating layer on one side and a stress compensation layer on the other side. That is, a first diffraction grating layer is provided on one surface of the first diffraction substrate, a second diffraction grating layer is provided on the other surface, and a third diffraction grating layer is provided on one surface of the second diffraction substrate. A lattice layer is provided and a stress compensation layer is provided on the other side.

According to one embodiment of the present invention, the first diffraction substrate including the first diffraction grating layer and the second diffraction grating layer and the second diffraction substrate including the third diffraction grating layer and the stress compensation layer The material can guide light incident on the first diffractive substrate and the second diffractive substrate to one point by internal reflection or total internal reflection. Specifically, the light incident on the first diffraction substrate is reflected or totally reflected inside the first diffraction substrate and emitted to a point different from the point where the light is incident on the first diffraction substrate. can do.

According to one embodiment of the present invention, the optical refractive index of each of the first diffraction substrate and the second diffraction substrate may be 1.5 or more and less than 2.0. Specifically, each of the first diffractive substrate and the second diffractive substrate can have an optical refractive index of 1.5 or more and less than 2.0 for light with a wavelength of about 500 nm. Also, the optical refractive index of the first diffraction substrate and the second diffraction substrate may be the same or different.

According to one embodiment of the present invention, the first diffractive base material and the second diffractive base material contain base materials commonly used in the industry as long as the base material maintains the optical refractive index within the above range. can be done. Specifically, glass or a resin film containing a high refractive component can be used as the first diffraction base material and the second diffraction base material. The _high refractive component may include at _{least one} of _TiO2 , _{Al2O3 , Ga2O3} , _TeO2 , ZrO2, _Ta2O5 , _{Nb2O5 ,} and ZnS. However, the types of the first diffraction base material and the second diffraction base material are not limited.

According to one embodiment of the present invention, one surface of the first diffractive substrate faces one surface or the other surface of the second diffractive substrate, or the other surface of the first diffractive substrate faces the second diffractive substrate. It can face one side or the other side of the diffractive substrate. Specifically, the first diffraction grating layer included on one surface of the first diffraction base is adjacent to the third diffraction grating layer included on one surface of the second diffraction base. The second diffractive substrate can be provided on the diffractive substrate. Also, the second diffraction substrate may be provided on the first diffraction substrate such that the first diffraction grating layer is adjacent to the stress compensation layer. Also, the second diffraction grating layer may be provided on the first diffraction substrate such that the second diffraction grating layer is adjacent to the third diffraction grating layer, and the second diffraction grating layer may The second diffractive substrate can be provided on the first diffractive substrate adjacent to the stress compensation layer.

3A-3D are diagrams schematically showing a diffractive light guide plate according to one embodiment of the present invention. Specifically, FIG. 3A shows a first diffractive substrate 100 with a first grating layer 310 on one side and a second grating layer 320 on the other side, and a third grating layer 320 on one side. A second diffraction substrate 200 having a grating layer 330 and a stress compensation layer 900 on the other surface is connected by a spacer 400. The other surface of the first diffraction substrate 100 and the second diffraction substrate 200 are connected. FIG. 10 is a diagram showing a diffractive light guide plate provided facing the other surface of the material 200; FIG. 3B shows a state in which one surface of the first diffraction substrate 100 provided with the first diffraction grating layer 310 and the other surface of the second diffraction substrate 200 provided with the stress compensation layer 900 are opposed to each other by the spacer 400 . FIG. 10 is a diagram showing coupled diffractive light guide plates; FIG. 3C shows a state in which the other surface of the first diffraction substrate 100 provided with the second diffraction grating layer 320 and the one surface of the second diffraction substrate 200 provided with the third diffraction grating layer 330 face each other. 4 shows a diffractive light guide plate connected by 400; FIG. FIG. 3D shows the spacer 400 with one surface of the first diffraction substrate 100 having the first diffraction grating layer 310 and one surface of the second diffraction substrate 200 having the third diffraction grating layer 330 facing each other. FIG. 10 is a diagram showing diffractive light guide plates connected by .

According to one embodiment of the present invention, the grating layer of the first diffractive substrate is separated from the second diffractive substrate. Specifically, the first diffraction base material and the second diffraction base material are arranged such that the first diffraction grating layer or the second diffraction grating layer is separated from the third diffraction grating layer or the stress compensation layer. provided separately from As shown in FIG. 3A, the second diffraction grating layer 320 of the first diffraction base 100 is separated from the stress compensation layer 900 of the second diffraction base 200 . Also, as shown in FIG. 3B, the first diffraction grating layer 310 of the first diffraction base 100 is separated from the stress compensation layer 900 of the second diffraction base 200 . Also, as shown in FIG. 3C, the second diffraction grating layer 320 of the first diffraction substrate 100 is separated from the third diffraction grating layer 330 of the second diffraction substrate 200 . Further, as shown in FIG. 3D, the first diffraction grating layer 310 of the first diffraction substrate 100 is separated from the third diffraction grating layer 330 of the second diffraction substrate 200 .

According to one embodiment of the present invention, the first diffractive substrate and the second diffractive substrate can be coupled in a spaced apart manner via a spacer. 3A to 3D, one end of the first diffraction base 100 and one end of the second diffraction base 200, the other end of the first diffraction base 100 and the second diffraction base The other end of 200 is connected by spacer 400 . The spacer may have a known structure capable of connecting the first diffraction base material and the second diffraction base material, and the spacer may be elastic.

According to one embodiment of the present invention, each of the thicknesses of the first diffractive substrate and the second diffractive substrate may be 0.1 mm or more and 2 mm or less. FIG. 3A shows the thickness h1 of the first diffraction substrate 100. As shown in FIG. The thickness of the first diffraction base material is 0.5 mm or more and 1.8 mm or less, 0.8 mm or more and 1.6 mm or less, 1 mm or more and 1.4 mm or less, 0.7 mm or more and 1 mm or less, or 1.1 mm or more and 1.8 mm. or less, or 1.3 mm or more and 1.5 mm or less. The first diffraction grating layer is provided on one side of the first diffraction substrate having the thickness described above, and the second diffraction grating layer is provided on the other side, thereby forming the first diffraction grating layer and the second diffraction grating layer. can be adjusted within the range described above. By adjusting the distance between the first diffraction grating layer and the second diffraction grating layer to the range described above, the first diffraction base material effectively separates the first light and the second light from the incident light. It can be divided and separated.

Further, the thickness of the second diffraction base material may be 0.1 mm or more and 2 mm or less, and is the thickness of the second diffraction base material the same as the thickness of the first diffraction base material? , can be different.

According to one embodiment of the present invention, the first diffraction grating layer separates light with a wavelength of 550 nm or more and 700 nm or less, the second diffraction grating layer separates light with a wavelength of 400 nm or more and 550 nm or less, The third diffraction grating layer can separate light with a wavelength of 450 nm or more and 650 nm or less. Specifically, the first diffraction grating layer can separate the first light having a wavelength value of 550 nm or more and 700 nm or less from the light incident on the first diffraction grating layer. Also, the second diffraction grating layer can separate a second light having a wavelength value of 400 nm or more and 550 nm or less from light incident on the second diffraction grating layer. Further, the third diffraction grating layer can separate third light having a wavelength value of 450 nm or more and 650 nm or less from light incident on the third diffraction grating layer.

The wavelength values of the light separated by the first diffraction grating layer, the second diffraction grating layer, and the third diffraction grating layer can be measured using a device for measuring the wavelength value of light in the art. As an example, it can be measured using an optical wavelength measuring device (86120C, Agilent Technologies).

According to one embodiment of the present invention, for a diffractive light guide plate including a first diffractive substrate 100 and a second diffractive substrate 200, as shown in FIG. When the first diffraction grating layer 310 is irradiated with incident light including light having various wavelength values, the first diffraction grating layer 310 has a wavelength value of 550 nm to 700 nm from the incident light. Light can be separated. After that, when the incident light passing through the first diffraction grating layer 310 is irradiated to the second diffraction grating layer 320, the second diffraction grating layer 320 absorbs the second light having a wavelength value of 400 nm or more and 550 nm or less from the incident light. can be separated. After that, when the incident light that has passed through the first diffraction grating layer 310 and the second diffraction grating layer 320 is irradiated onto the third diffraction grating layer 330, the third diffraction grating layer 320 has a wavelength of 450 nm or more and 650 nm or less from the incident light. A third light having a wavelength value can be separated.

In addition, as shown in FIG. 3B, when incident light is applied to the second diffraction grating layer 320 with respect to the diffraction light guide plate including the first diffraction base 100 and the second diffraction base 200, the second diffraction grating Layer 320 can separate the secondary light from the incident light. After that, when incident light passing through the second diffraction grating layer 320 is applied to the first diffraction grating layer 310, the first diffraction grating layer 310 can separate the first light from the incident light. After that, when the incident light that has passed through the second diffraction grating layer 320 and the first diffraction grating layer 310 is irradiated onto the third diffraction grating layer 330, the third diffraction grating layer 330 separates the third light from the incident light. can do.

In the case of the diffraction light guide plates of FIGS. 3C and 3D, the first light, the second light, and the third light are separated from the first incident light in the same manner as the diffraction light guide plates of FIGS. 3A and 3B. be done.

According to one embodiment of the present invention, said first diffractive substrate comprising a first diffraction grating layer on one side and a second diffraction grating layer on the other side is arranged such that the light incident on the first diffractive substrate is The first light and the second light can be more effectively divided and separated. Specifically, the first diffraction base includes a first diffraction grating layer on one surface and a second diffraction grating layer on the other surface. The first light having a wavelength value is separated, and the second diffraction grating layer separates the second light having a wavelength value of 400 nm or more and 550 nm or less, thereby preventing crosstalk between the first light and the second light. (cross talk) can be prevented from occurring.

That is, a crosstalk phenomenon occurs between the first light separated by the first diffraction grating layer provided on the single first diffraction substrate and the second light separated by the second diffraction grating layer. By preventing this, the thickness and weight of the diffractive light guide plate can be reduced, and at the same time, the light separation efficiency of the first diffractive substrate can be improved. In addition, it is possible to improve the light diffraction efficiency of the first diffractive base material, and to effectively suppress the occurrence of the double image phenomenon and the chromatic dispersion phenomenon.

FIG. 4A shows the in-coupling angle and out-coupling of the first diffraction substrate with the first grating layer and the second grating layer according to one embodiment of the present invention. 4B shows the in-coupling angle and the out-coupling angle of the diffraction substrate provided with the first grating layer and the third grating layer. - indicates the out-coupling angle. Specifically, FIG. 4A shows in-coupling and out-coupling angles of a first diffractive substrate provided with a first grating layer and a second grating layer according to an embodiment of the present invention. and a diagram showing a form in which light incident on the first diffraction base material is reflected within the base material. Also, FIG. 4B is a diagram showing in-coupling angles and out-coupling angles of a diffractive substrate provided with a first grating layer and a third grating layer, unlike an embodiment of the present invention. and a form in which light incident on the diffraction base material is reflected within the base material.

Referring to FIG. 4A, the first diffraction grating layer for separating light with a wavelength of 550 nm to 700 nm and the second diffraction grating for separating light with a wavelength of 400 nm to 550 nm according to an embodiment of the present invention. In the case of the first diffractive substrate comprising a layer, no crosstalk phenomenon occurs in the first diffractive substrate, no double images occur in the field of view, and as set in the first diffractive substrate It can be confirmed that light diffraction occurs. In contrast, referring to FIG. 4B, the first grating layer separates light with a wavelength of 550 nm to 700 nm and the third grating layer separates light with a wavelength of 450 nm to 650 nm. In the case of a diffractive substrate, the crosstalk phenomenon occurs in the diffractive substrate, and the crosstalk phenomenon causes the phenomenon of double images and chromatic dispersion in the viewing range, causing the light to differ from that set within the diffractive substrate. It can be confirmed that diffraction occurs.

At this time, the in-coupling angle and out-coupling angle of the diffractive substrate in FIGS. 4A and 4B are used in the industry for simulating the in-coupling angle and out-coupling angle of the diffractive substrate. / or can be measured using a method.

In the present invention, the in-coupling angle and the out-coupling angle of the diffractive substrate can be simulated using Equation 1 below.
[Formula 1]
sin(θ _in )−sin(θ _out )=λ(1/b−1/a)

In Equation 1, θ _in means an in-coupling angle, and θ _out means an out-coupling angle. In Equation 1, λ is the wavelength, a is the period of the diffraction grating that diffracts the incident light into the diffraction substrate, and b is the diffraction grating that diffracts the light inside the diffraction substrate to the angle of the outgoing light. is the cycle of When in-coupling and out-coupling occur in the same plane, i.e., when a=b, the angles of the incident and outgoing light are the white circles located in the viewing range in FIGS. 4A and 4B. are identical as expressed in On the other hand, if the in-coupling and the out-coupling occur in different planes, that is, if a≠b, then the in-coupling angle and the out-coupling angle are different, which depends on the wavelength. chromatic dispersion occurs. FIG. 4A is the result of calculating the out-coupling angle according to the in-coupling angle when a is 468 nm and b is 405 nm, or when a is 405 nm and b is 468 nm. expressed in FIG. 4B is the result of calculating the out-coupling angle according to the in-coupling angle when a is 468 nm and b is 340 nm, or when a is 304 nm and b is 468 nm. expressed in

According to one embodiment of the present invention, the optical refractive index of each of the first to third diffraction grating layers may be 1.5 or more and less than 2. Each of the first to third diffraction grating layers may have a refractive index of 1.5 or more and less than 2.0 with respect to light having a wavelength of about 500 nm.

Specifically, the optical refractive index of each of the first to third diffraction grating layers is 1.55 or more and 1.9 or less, 1.6 or more and 1.8 or less, or 1.7 or more and 1.8 or less. , 1.5 to 1.8, or 1.55 to 1.75.

Each of the first diffraction grating layer, the second diffraction grating layer, and the third diffraction grating layer having the optical refractive index within the range may have excellent diffraction performance with respect to incident light. When the optical refractive index of each of the first to third diffraction grating layers is 2 or more, a problem of secondary diffraction may occur, and when the optical refractive index is less than 1.5, , the light diffraction efficiency of the diffractive light guide plate may be reduced.

Also, the optical refractive indices of the first diffraction grating layer, the second diffraction grating layer, and the third diffraction grating layer may be the same or different.

According to one embodiment of the present invention, the optical refractive index of the diffraction grating layer, the optical refractive index of the diffraction substrate, and the like can be measured using a method for measuring optical refractive index generally in the industry. can. As an example, a prism coupler (SPA-4000) or an ellipsometry can be used to measure the optical refractive index.

According to one embodiment of the present invention, each of said _first grating layer, _second grating layer and _third grating layer is _TiO2 , _{Al2O3 , Ga2O3} , TeO2, ZrO2. , Ta ₂ O ₅ , Nb ₂ O ₅ , ZnS, HfO, MoO, and CuO. However, it does not limit the high refractive components contained in the first diffraction grating layer, the second diffraction grating layer, and the third diffraction grating layer. The optical refractive index of the diffraction grating layer can be controlled by adjusting the content and type of the high refractive component contained in the diffraction grating layer.

According to one embodiment of the present invention, each of the first diffraction grating layer, the second diffraction grating layer, and the third diffraction grating layer contains a thermosetting resin or a photocurable resin containing a high refractive component. can be done. Specifically, the thermosetting resin or photosetting resin can include acrylic resins such as urethane acrylate and epoxy acrylate, polyamide resins, polyimide resins, silicon resins, epoxy resins, polyester resins, and the like. The type is not limited.

According to one embodiment of the present invention, the optical refractive indices of the first grating layer and the second grating layer may be the same as or different from the optical refractive index of the first diffraction substrate. Further, the optical refractive index of the third diffraction grating layer and the second diffraction substrate may be the same or different.

According to one embodiment of the present invention, the stress compensation layer may contain a thermosetting resin or a photo-setting resin. Specifically, the thermosetting resin or photosetting resin can include acrylic resins such as urethane acrylate and epoxy acrylate, polyamide resins, polyimide resins, silicon resins, epoxy resins, polyester resins, and the like. The type is not limited. Also, the stress compensation layer may contain a thermosetting resin or a photosetting resin containing high refractive particles. The high refractive particles include at least one of TiO ₂ , Al ₂ O ₃ , Ga ₂ O ₃ , TeO ₂ , ZrO ₂ , Ta ₂ O ₅ , Nb ₂ O ₅ , ZnS, HfO, MoO, and CuO. can contain.

According to one embodiment of the present invention, each of the first to third diffraction grating layers has a first region where light is incident, a second region where incident light is diffused and moved, and a moving region. and a third region from which the light is extracted, wherein the first regions are included in corresponding positions of the first to third diffraction grating layers, and the third region is the third region. They are included in positions corresponding to each other from the first diffraction grating layer to the third diffraction grating layer.

FIG. 5 is a diagram schematically showing a plane of a first diffraction grating layer according to one embodiment of the present invention. Specifically, FIG. 5 shows a first region 511 including a first region 511 where light is incident, a second region 512 where the incident light is diffused and moved, and a third region 513 where the moved light is extracted. 3 is a diagram showing a plane of a diffraction grating layer 310; FIG. As shown in FIG. 5, a first region 511 to a third region 513 are sequentially provided from one side A to the other side B of the first diffraction grating layer 310 . At this time, the pattern structure of the first diffraction grating layer is omitted from FIG.

Referring to FIG. 5, the first area 511 may be an area where incident light including light having various wavelength values is incident. In addition, the second region 512 is a region where light incident on the first diffraction grating layer 310 is diffracted, and a region where light incident on the first region 511 is expanded to the third region 513 . could be. The third area 513 is an area from which light is extracted. When the diffraction light guide plate is used in a display unit, the third area 513 may be an area from which light is extracted to provide display information to a user. Further, similar to the first grating layer shown in FIG. 5, the second and third grating layers can also include first through third regions.

FIG. 6 is a diagram schematically showing a cross section of a first diffraction substrate including a first diffraction grating layer according to one embodiment of the present invention; Specifically, FIG. 6 is a diagram showing that after the light is incident on the first area 511, the light is extracted to the third area 513 to provide display information to the user. In FIG. 6, the second diffraction grating layer included on the other surface of the first diffraction base material and the second diffraction base material are omitted from the illustration. In FIG. 6, the second diffraction grating layer included on the other surface of the first diffraction substrate is omitted. Also, as shown in FIG. 6, in the second diffraction grating layer and the third diffraction grating layer, light incident on the first region is extracted through the third region.

According to one embodiment of the present invention, each of the first to third diffraction grating layers may include a diffraction pattern. The diffraction pattern can include two or more pattern structures.

FIG. 7 is a schematic diagram of a first grating layer including a diffraction pattern according to one embodiment of the present invention. Specifically, FIG. 7 is a diagram showing a diffraction pattern including two or more pattern structures provided along the direction from one side A to the other side B of the first diffraction grating layer 310 . In FIG. 7, the second diffraction grating layer included on the other surface of the first diffraction substrate is omitted. Similar to that shown in FIG. 7, the second grating layer and the third grating layer have a diffraction pattern comprising two or more pattern structures provided along the direction from one side to the other side of the grating layer. can contain.

According to an embodiment of the present invention, the first diffraction grating layer, the second diffraction grating layer, and the third diffraction grating layer are formed according to the form of the diffraction patterns included in the first to third diffraction grating layers. The wavelength values of the light separated from the light incident on may be different.

FIG. 8 is a diagram schematically showing a cross section of a diffraction pattern included in a first diffraction grating layer according to one embodiment of the invention. Specifically, FIG. 8 shows a diffraction pattern comprising two or more patterned structures. In FIG. 8, the second diffraction grating layer included on the other surface of the first diffraction substrate is omitted. Referring to FIG. 8, a pattern structure is provided at an inclination angle of θ1 from one surface of the first diffraction substrate 100, the pattern structure has a height of h2, and two or more pattern structures are provided. are provided with a pitch of d1. In the present invention, the 'period' means the interval at which the pattern structure is repeated, and as shown in FIG. can mean the length between One point of one pattern structure and one point of another pattern structure may mean positions corresponding to each other between the pattern structures.

Referring to FIG. 8, the pattern structures included in the diffraction pattern of the first diffraction grating layer 310 according to an embodiment of the present invention are inclined from one surface of the first diffraction substrate 100 by 50° or more and less than 90°. provided at an angle θ1. Also, the two or more pattern structures may have a period d1 of 100 nm to 600 nm, and the height h2 of the pattern structures may be more than 0 nm and 600 nm or less. Specifically, the inclination angles of the pattern structures included in the first diffraction grating layer with respect to the first diffraction substrate are 55° to 80°, 60° to 75°, 65° to 85°. It may be 50° or more and 65° or less, or 70° or more and 80° or less. Further, the two or more pattern structures are provided with a period of 150 nm to 500 nm, 200 nm to 400 nm, 250 nm to 350 nm, 150 nm to 250 nm, 350 nm to 450 nm, or 500 nm to 600 nm. The height of the pattern structure may be 10 nm to 500 nm, 50 nm to 400 nm, 100 nm to 350 nm, 150 nm to 250 nm, 450 nm to 550 nm, or 300 nm to 400 nm.

According to an embodiment of the present invention, similar to said first grating layer, said second grating layer and said third grating layer may comprise two or more pattern structures, said pattern structures The body is provided at an angle of inclination of 50° or more and less than 90° from one side of the diffractive substrate. Also, the two or more pattern structures may be provided with a period of 100 nm or more and 600 nm or less, and the height of the pattern structures may be more than 0 nm and less than or equal to 600 nm. Specifically, the pattern structure included in each of the second diffraction grating layer and the third diffraction grating layer is oriented at 50° to 80°, 55° to 70°, 65° with respect to one surface of the diffraction substrate. It may have an inclination angle of 75° or more, or 70° or more and 80° or less. Further, the two or more pattern structures are provided with a period of 125 nm to 450 nm, 250 nm to 350 nm, 200 nm to 400 nm, 150 nm to 300 nm, 350 nm to 400 nm, or 500 nm to 655 nm. The height of the pattern structure may be 30 nm to 500 nm, 100 nm to 400 nm, 150 nm to 300 nm, 200 nm to 250 nm, 450 nm to 550 nm, or 300 nm to 400 nm.

According to one embodiment of the present invention, the forms of diffraction patterns included in the first diffraction grating layer, the second diffraction grating layer and the third diffraction grating layer may be different. As an example, the pattern structures included in the diffraction pattern of the first diffraction grating layer and the pattern structures included in the diffraction pattern of the second diffraction grating layer have the same period, but the inclination of the pattern structures Angles and heights can be different. Further, the pattern structure included in the diffraction pattern of the second diffraction grating layer and the pattern structure included in the diffraction pattern of the third diffraction grating layer have the same height, but the tilt angle of the grating is different. can be different.

Therefore, according to one embodiment of the present invention, the tilt angle formed by the pattern structures included in the diffraction pattern of the diffraction grating layer with respect to the diffraction substrate, the pitch between the pattern structures, and the height of the pattern structures The depth can be adjusted to easily control the wavelength value of the light separated from the light incident on the grating layer.

FIG. 9 shows simulation results of the optical diffraction efficiency of the diffraction grating layer according to the duty, height, and optical refractive index of pattern structures included in the diffraction grating layer according to one embodiment of the present invention. Specifically, in FIG. 9A, the optical refractive index (n) of the diffraction grating layer is set to 1.8, and the height (depth) is set to 300 nm. It shows the simulation result of the optical diffraction efficiency. In addition, FIG. 9B shows the optical refractive index (n) of the diffraction grating layer set to 1.8 and the duty (duty) set to 0.6, and the light of the diffraction grating layer according to the height of the pattern structure. 4 shows simulation results of diffraction efficiency. Further, FIG. 9C shows a diffraction grating layer whose duty is 0.6 and whose depth is set to 300 nm and which corresponds to the refractive index of the pattern structure. Fig. 3 shows simulation results of the optical diffraction efficiency of .

Referring to FIGS. 9(a) to 9(c), the duty and height of the pattern structures included in the diffraction grating layer and the optical refractive index of the diffraction grating layer are adjusted according to an embodiment of the present invention. Thus, it can be confirmed that the optical diffraction efficiency of the diffraction grating layer can be easily controlled.

At this time, the simulations in FIGS. 9(a) to 9(c) can be calculated using an apparatus and/or method for calculating the optical diffraction efficiency of a diffractive substrate in the art. , can be calculated using VirtualLab SoftWare, which utilizes the Rigorous Coupled Wave Analysis algorithm.

10A and 10B are diagrams schematically showing cross sections of a diffraction light guide plate including first to third diffraction grating layers according to one embodiment of the present invention. Specifically, FIG. 10A shows first diffraction patterns 311, 321, 331, second diffraction patterns 312, 322, and 333 included in second regions 512, 522, and 532, and third diffraction patterns 313, 323, and 333 included in third regions 513, 523, and 533. FIG. 10B shows first diffraction patterns 311 and 321 included in first regions 511 and 521 and second diffraction patterns included in second regions 512 and 522 of first diffraction grating layer 310 and second diffraction grating layer 320, respectively. The patterns 312 and 322 and the third diffraction patterns 313 and 323 included in the third regions 513 and 523 are shown. Fig. 10 shows that a third diffraction pattern 333 and two second regions 532, 532' each include a second diffraction grating pattern 332, 332'.

According to one aspect of the present invention, the first regions are included in corresponding positions of the first to third diffraction grating layers, and the third regions are the first diffraction grating layers. layer to the third diffraction grating layer at positions corresponding to each other. That is, the first regions included in each of the first to third diffraction grating layers are aligned to be provided at positions corresponding to each of the first to third diffraction grating layers. be done. The third regions included in each of the first to third diffraction grating layers are aligned so as to be provided at positions corresponding to each of the first to third diffraction grating layers. be done.

According to one embodiment of the present invention, a location provided with a first region of the first grating layer, a location provided with a first region of the second grating layer, and a first region of the third grating layer The positions at which the regions are provided can correspond to each other. Specifically, the positions of the first diffraction grating layer to the third diffraction grating layer including the first region may be the same, and the positions of the first diffraction grating layer to the third diffraction grating layer including the third region may be the same. The positions of the layers may be identical to each other.

According to one embodiment of the present invention, the position where the first region of the first diffraction grating layer is provided and the position where the first region of the second diffraction grating layer is provided can correspond, and The position where the first region of the second diffraction grating layer is provided can correspond to the position where the first region of the third diffraction grating layer is provided, and the position where the first region of the first diffraction grating layer is provided. can correspond to the position where the first region of the third diffraction grating layer is provided.

Further, the position where the third region of the first diffraction grating layer is provided, the position where the third region of the second diffraction grating layer is provided, and the position where the third region of the third diffraction grating layer is provided are mutually can respond. That is, the position where the third region of the first diffraction grating layer is provided can correspond to the position where the third region of the second diffraction grating layer is provided, and the third region of the second diffraction grating layer can correspond to the position where the third region of the second diffraction grating layer is provided. can correspond to the position where the third region of the third diffraction grating layer is provided, and the position where the third region of the first diffraction grating layer is provided and the position of the third diffraction grating layer can correspond to the position where the third region of is provided. The first light separated from the first diffraction grating layer is separated from the second light from the second diffraction grating layer by the positions of the third regions provided in the first to third diffraction grating layers corresponding to each other. The second light that is coupled and the third light that is separated from the third grating layer are effectively combined.

Also, an area between the first regions and an area between the third regions aligned to correspond to each other in the first to third diffraction grating layers may be substantially the same. In the present invention, "the area is substantially the same" means not only that the area is exactly the same, but also that the area including minute errors that may occur in manufacturing is the same. can also

10A and 10B, the positions of the first regions 511, 521, and 531 included in the first diffraction grating layer 310, the second diffraction grating layer 320, and the third diffraction grating layer 330 correspond to each other. can do. Also, the positions of the third regions 513, 523, 533 included in the first diffraction grating layer 310, the second diffraction grating layer 320, and the third diffraction grating layer 330 may correspond to each other. That is, the first region and the third region included in each of the first to third diffraction grating layers are provided at positions corresponding to the first to third diffraction grating layers. Furthermore, each of the first regions included in the first to third diffraction grating layers may have substantially the same area, and each of the first to third diffraction grating layers may have substantially the same area. may have substantially the same area. A display to which the diffraction light guide plate is applied by forming the first region and the third region included in the first diffraction grating layer, the second diffraction grating layer, and the third diffraction grating layer at positions corresponding to each other. The quality, such as sharpness, of the images realized by the unit can be improved.

Meanwhile, according to an embodiment of the present invention, the second regions included in each of the first diffraction grating layer, the second diffraction grating layer, and the third diffraction grating layer are provided at positions corresponding to each other, or provided for different positions. Referring to FIG. 10A, second regions 512, 522, and 532 included in the first diffraction grating layer 310, the second diffraction grating layer 320, and the third diffraction grating layer 330 are provided at positions corresponding to each other. . Also, referring to FIG. 10B, the second region 512 provided in the first diffraction grating layer 310 and the third region 533 provided in the third diffraction grating layer 330 may have different positions and areas. .

According to an embodiment of the present invention, the first to third diffraction grating layers may include first and third regions, and optionally include second regions. As an example, the first grating layer and the third grating layer may include the first to third regions, and the second grating layer may include only the first and third regions.

According to one embodiment of the present invention, a plurality of first regions, second regions, and third regions included in each of the first diffraction grating layer, the second diffraction grating layer, and the third diffraction grating layer are formed. be done. As an example, the third diffraction grating layer may include one first region, two second regions, and one third region. Referring to FIG. 10B, the third grating layer 330 can include two second regions 532, 532', each of which has a second diffraction pattern 332, 332'. can include

According to one aspect of the present invention, the first diffraction pattern, the second diffraction pattern, and the third diffraction pattern included in each of the first to third diffraction grating layers have different forms. may As an example, the pattern structure included in the first diffraction pattern of the first diffraction grating layer and the pattern structure included in the second diffraction pattern of the first diffraction grating layer are different from each other. The corners, heights, widths, etc. may be different. Further, the pattern structure included in the first diffraction pattern of the first diffraction grating layer and the pattern structure included in the first diffraction pattern of the second diffraction grating layer are defined in the tilt direction of the pattern structure, Inclination angles, heights, widths, etc. may be different.

FIG. 11 is a schematic diagram of a first diffraction grating layer including first to third diffraction patterns according to one embodiment of the present invention. Specifically, FIG. 11 shows the tilt directions and tilt directions of the pattern structures included in the first diffraction pattern 311, the pattern structures included in the second diffraction pattern 312, and the pattern structures included in the third diffraction pattern 313. FIG. 3 is a diagram showing first diffraction grating layers 310 having different angles, periods, and heights; In FIG. 11, the second diffraction grating layer included on the other surface of the first diffraction substrate is omitted.

Referring to FIG. 11 , the tilt direction, tilt angle, and tilt angle between the pattern structures included in the first diffraction pattern 311, the second diffraction pattern 312, and the third diffraction pattern 313 of the first diffraction grating layer 310 and the diffraction substrate. By adjusting the period of the pattern structure and the height of the pattern structure, the efficiency of separating the first light from the light incident on the first diffraction grating layer and the diffraction efficiency of the light with respect to the first diffraction substrate are improved. be able to. Further, as with the first diffraction grating layer, the tilt directions and tilt angles of the pattern structures included in the first diffraction pattern, the second diffraction pattern, and the third diffraction pattern of the second diffraction grating layer and the third diffraction grating layer , the period of the pattern structures, and the height of the pattern structures can be adjusted.

Therefore, according to one embodiment of the present invention, a diffraction grating that can manufacture a display that realizes a clear image can be manufactured by adjusting the tilt angle, period, height, etc. of the pattern structures included in the diffraction pattern of the diffraction grating layer. A light guide plate can be provided.

According to an embodiment of the present invention, the third regions of the first to third diffraction grating layers may have optical refractive indices that gradually increase from one side to the other side.

In a conventional diffractive light guide plate, the light diffraction efficiency is the same in all areas where light is extracted to provide display information to the user. If the light diffraction efficiency is the same over the entire area of the diffraction light guide plate where light is diffracted, the amount of light diffracted by the diffraction light guide plate decreases while the light is reflected or totally reflected inside the diffraction light guide plate. Specifically, when light is incident on one side of the diffraction light guide plate and is guided to the other side of the diffraction light guide plate, the amount of light diffracted in the diffraction area increases from one side to the other side of the diffraction light guide plate. decreases. When the amount of diffracted light is different for each part of the diffractive light guide plate, high-intensity light is emitted from a part with a large amount of diffracted light, but low-intensity light is emitted from a part with a small amount of diffracted light. Therefore, in the case of the conventional diffractive light guide plate, the light diffraction efficiency is the same throughout the light extraction area, and the luminous intensity of the light extracted from each part of the light extraction area may be uneven.

On the other hand, according to an embodiment of the present invention, the optical refractive index of the third regions of the first to third diffraction grating layers may gradually increase from one side to the other side. can. The third region is a region from which light is extracted, and the third region has a gradual increase in optical refractive index from one side to the other so that the amount of light extracted from each portion of the third region is The light intensity can be constant. Therefore, according to an embodiment of the present invention, it is possible to realize a diffractive light guide plate capable of providing the user with display information having the same luminosity.

In addition, like the third region, the optical refractive index of the first region and/or the second region included in each of the first to third diffraction grating layers gradually increases from one side to the other side. can do.

According to an embodiment of the present invention, the third region may include a diffraction pattern including slanted pattern structures whose heights gradually increase from one side to the other side. Specifically, the third region includes a diffraction pattern including slanted pattern structures whose heights gradually increase from one side to the other side, thereby increasing the optical refractive index from one side to the other side of the third region. can be increased progressively. Referring to FIG. 11, the third region 513 includes a diffraction pattern including a slanted pattern structure whose height gradually increases from one side A to the other side B of the third region 513 . The optical refractive index may gradually increase from one side to the other side of the third region. As the optical refractive index gradually increases from one side to the other side of the third region, the optical diffraction efficiency may gradually increase from one side to the other side of the third region.

Therefore, according to one embodiment of the present invention, the height of the inclined pattern structure included in the third region of the first to third diffraction grating layers is increased in the direction from one side of the third region to the other side. By gradually increasing along the direction of the third region, the light intensity is prevented from decreasing while the light is diffracted from one side of the third region to the other side, and the luminous intensity of the light emitted from each portion of the third region is prevented. can be made constant.

In addition, like the third region, the first region and/or the second region included in each of the first to third diffraction grating layers gradually increase in height from one side to the other side. A diffraction pattern comprising tilted pattern structures can be included.

According to an embodiment of the present invention, the third area may include a pattern structure whose duty increases gradually from one side to the other side. In the present invention, the 'duty' may mean a value obtained by dividing the width of the pattern structure by the period of the pattern structure (width of pattern structure/period of pattern structure). Referring to FIG. 8, the duty of the pattern structure may be d2/d1, which is the width d2 of the pattern structure divided by the period d1 of the pattern structure.

According to an embodiment of the present invention, the third region includes a pattern structure whose duty gradually increases from one side to the other side, thereby increasing the optical refractive index from one side to the other side of the third region. It can be increased incrementally. As the duty of the pattern structure gradually increases from one side to the other side of the third area, the optical refractive index may gradually increase from one side to the other side of the third area. can. As the optical refractive index gradually increases from one side to the other side of the third region, the optical diffraction efficiency may gradually increase from one side to the other side of the third region. As an example, by setting the period of the pattern structures to be the same and gradually increasing the width of the pattern structures, the duty of the pattern structures is gradually increased from one side to the other side of the third region. can be increased.

According to an embodiment of the present invention, the duty of the pattern structures included in the third region may be 0.1 or more and 1.0 or less. By adjusting the duty of the pattern structure included in the third region to the range described above, the third region having excellent light diffraction efficiency can be realized.

According to one embodiment of the present invention, the period of the two or more pattern structures is set to be the same, and the width of the pattern structures is gradually increased from one side to the other side of the third region, thereby forming the pattern. The duty of the structure can be progressively increased from one side of the third region to the other.

Further, like the third region, the first region and/or the second region included in each of the first to third diffraction grating layers has a pattern in which the duty increases gradually from one side to the other side. Can contain structures.

Also, another embodiment of the present invention provides a method of manufacturing a diffractive light guide plate.

An embodiment of the present invention comprises the steps of providing a first diffractive substrate comprising a first grating layer on one side and a second grating layer on the other side; a third grating layer on one side; A method for manufacturing the diffractive light guide plate, comprising: providing a second diffractive substrate including a stress compensation layer on the other surface; and bonding the first diffractive substrate and the second diffractive substrate. offer.

According to one embodiment of the present invention, it is possible to easily manufacture a diffractive light guide plate with reduced thickness and weight.

Further, according to one embodiment of the present invention, it is possible to easily manufacture a diffractive light guide plate that includes the first diffractive base and the second diffractive base that are prevented from bending.

A first diffraction base material, a second diffraction base material, a first diffraction grating layer, a second diffraction grating layer, a third diffraction grating layer, and stress compensation manufactured by a method for manufacturing a diffraction light guide plate according to an embodiment of the present invention The layers are the first diffraction base material, the second diffraction base material, the first diffraction grating layer, the second diffraction grating layer, the third diffraction grating layer, and the stress compensation layer included in the diffraction light guide plate according to one embodiment of the present invention. may be substantially the same as

According to one embodiment of the present invention, the step of preparing the first diffraction substrate includes forming the first diffraction grating layer on one surface of the first substrate and forming the first diffraction grating layer on the other surface of the first substrate. The first diffraction substrate may be manufactured by forming the second diffraction grating layer. Specifically, after forming the first diffraction grating layer on one surface of the first substrate, the second diffraction grating layer can be formed on the other surface of the first substrate. Also, the first diffraction grating layer and the second diffraction grating layer can be simultaneously formed on one surface and the other surface of the first base material.

According to one embodiment of the present invention, the step of preparing the first diffraction base includes: a first base having the first diffraction grating layer on one side and a second diffraction grating layer on one side; Additional substrates provided can be bonded together to produce a first diffractive substrate. Specifically, after forming a first diffraction grating layer on one surface of the first substrate and forming a second diffraction grating layer on one surface of the additional substrate, the other surface of the first substrate and The first diffractive base material can be manufactured by joining the other surface of the additional base material.

According to one embodiment of the present invention, the other surface of the first base material and the other surface of the additional base material are bonded via an adhesive layer. The adhesive layer can maintain an optical refractive index of 1.5 or more and less than 2.0. By bonding the first base material and the additional base material using an adhesive layer that maintains the optical refractive index within the range described above, a first diffractive base material having excellent optical diffraction efficiency can be manufactured. can.

According to one embodiment of the present invention, the adhesive layer may include an adhesive film or an adhesive. Specifically, the adhesive film that maintains the optical refractive index described above can be used, and the adhesive that can form the adhesive layer that maintains the optical refractive index described above can be used.

According to one embodiment of the present invention, the step of preparing the second diffraction substrate includes forming the third diffraction grating layer on one surface of the second substrate and forming the third diffraction grating layer on the other surface of the second substrate. The stress compensation layer may be formed to manufacture the second diffractive substrate. Specifically, after forming the third diffraction grating layer on one surface of the second substrate, the stress compensation layer may be formed on the other surface of the second substrate. Also, the third diffraction grating layer and the stress compensation layer may be simultaneously formed on one surface and the other surface of the second base material.

According to one embodiment of the present invention, the step of providing the second diffractive substrate includes: a second substrate having the third diffraction grating layer on one side; and a stress compensation layer having the stress compensation layer on one side. Additional substrates thus formed can be bonded together to produce a second diffractive substrate. Specifically, after forming a third diffraction grating layer on one surface of the second substrate and forming a stress compensation layer on one surface of the additional substrate, the other surface of the second substrate and the additional substrate are formed. The second diffractive base material can be manufactured by bonding the other surface of the base material of the above.

According to one embodiment of the present invention, the other surface of the second base material and the other surface of the additional base material are bonded via an adhesive layer. The adhesive layer that bonds the other surface of the second base material and the other surface of the additional base material is the same as the adhesive layer that bonds the other surface of the first base material and the other surface of the additional base material. may be

According to one embodiment of the present invention, the step of providing the second diffractive substrate may form an antireflection pattern on the stress compensation layer. By forming the antireflection pattern on the stress compensation layer, it is possible to effectively suppress reflection of external light incident on the second diffraction substrate. Also, the anti-reflection pattern may be an anti-reflection pattern used in the industry. As an example, in the present invention, a moth-eye pattern can be formed on the surface of the stress compensation layer as an antireflection pattern.

According to one embodiment of the present invention, the first to third diffraction grating layers and the stress compensation layer are each formed using an imprinting process using a photocurable resin composition and an imprint mold. be done.

According to one embodiment of the present invention, the step of preparing the first diffraction substrate includes coating a photocurable resin composition on the first substrate and forming a diffraction pattern on the surface of the photocurable resin composition. can be imprinted using a mold having an intaglio surface. After that, the photocurable resin composition can be irradiated with light to photocure the photocurable resin composition. As a result, the first substrate having the first diffraction grating layer formed on one surface can be manufactured. The intaglio grating pattern on the mold can correspond to the pattern of the first grating layer.

According to one embodiment of the present invention, a photocurable resin composition is applied to the other surface of the first substrate on which the first diffraction grating layer is formed, and the photocurable resin composition is coated on the other surface of the first substrate. can be imprinted using a mold having a surface on which a diffraction pattern is engraved. After that, the photocurable resin composition can be irradiated with light to photocure the photocurable resin composition. The intaglio grating pattern in the mold can correspond to the pattern of the second grating layer. As a result, the first diffraction base material having the first diffraction grating layer formed on one side and the second diffraction grating layer formed on the other side can be manufactured.

According to one embodiment of the present invention, the step of photocuring the photocurable resin composition is performed simultaneously with the step of imprinting a mold on the surface of the photocurable resin composition, or the mold is removed. It may be done later.

According to one embodiment of the present invention, after the first diffraction grating layer is formed on one surface of the first base material, a release film or the like is attached to the first diffraction grating layer to form the first base material. The first grating layer may be protected during the process of forming the second grating layer on the other side.

Further, according to one embodiment of the present invention, the photocurable resin composition is simultaneously coated on one surface and the other surface of the first substrate, dried, and coated on the one surface and the other surface of the first substrate. The surface of the photocurable resin composition thus formed may be imprinted at the same time using a mold.

According to one embodiment of the present invention, the step of preparing the first diffraction substrate includes coating a photocurable resin composition on the first substrate and forming a diffraction pattern on the surface of the photocurable resin composition. can be imprinted using a mold having an intaglio surface. Then, the photocurable resin composition is photocured to manufacture a first substrate having a first diffraction grating layer formed on one surface thereof. A photocurable resin composition can be applied onto an additional substrate, and imprinting can be performed using a mold having a surface in which a diffraction pattern is engraved on the surface of the photocurable resin composition. After that, the photocurable resin composition can be photocured to produce an additional substrate having a second diffraction grating layer formed thereon. After that, the other surface of the first base material and the other surface of the additional base material are bonded via an adhesive layer to manufacture the first diffraction base material.

According to one embodiment of the present invention, the step of preparing the second diffraction substrate includes coating a photocurable resin composition on the second substrate, and forming a diffraction pattern on the surface of the photocurable resin composition. can be imprinted using a mold having an intaglio surface. After that, the photocurable resin composition can be irradiated with light to photocure the photocurable resin composition. As a result, a second substrate having a third diffraction grating layer formed on one surface can be manufactured. The intaglio grating pattern in the mold can correspond to the pattern of the third grating layer.

According to one embodiment of the present invention, a photocurable resin composition is applied to the other surface of the second substrate having the third diffraction grating layer formed on one surface, and the photocurable resin composition is coated on the other surface of the second substrate. can be imprinted using a mold having a surface on which the anti-reflection pattern is engraved. After that, the photocurable resin composition can be irradiated with light to photocure the photocurable resin composition. The intaglio antireflection pattern on the mold can correspond to the antireflection pattern on the second grating layer. Accordingly, a second diffraction substrate having a third diffraction grating layer formed on one surface and a stress compensation layer including an antireflection pattern formed on the other surface can be manufactured.

According to one embodiment of the present invention, the step of photocuring the photocurable resin composition is performed simultaneously with the step of imprinting a mold on the surface of the photocurable resin composition, or the mold is removed. It may be done later.

According to one embodiment of the present invention, after forming the third diffraction grating layer on one surface of the second base material, a release film or the like is attached to the third diffraction grating layer to form the second base material. The third grating layer may be protected during the process of forming a stress compensation layer on the other side.

Further, according to one embodiment of the present invention, the photocurable resin composition is simultaneously coated on one surface and the other surface of the second substrate, dried, and coated on the one surface and the other surface of the second substrate. The surface of the photocurable resin composition thus formed may be imprinted at the same time using a mold.

According to one embodiment of the present invention, the step of preparing the second diffraction substrate includes coating a photocurable resin composition on the second substrate, and forming a diffraction pattern on the surface of the photocurable resin composition. can be imprinted using a mold having an intaglio surface. Then, the photocurable resin composition is photocured to manufacture a second substrate having a third diffraction grating layer formed on one surface thereof. A photocurable resin composition can be applied onto an additional substrate and imprinted using a mold having a surface in which an antireflection pattern is engraved on the surface of the photocurable resin composition. After that, the photocurable resin composition can be photocured to produce an additional substrate having a stress compensation layer formed on one surface thereof. After that, the other surface of the second base material and the other surface of the additional base material are bonded via an adhesive layer to manufacture the second diffraction base material.

According to one embodiment of the present invention, the photocurable resin composition used to form the third grating layer from the first grating layer comprises _TiO2 , _{Al2O3 , Ga2O} . ₃ , _TeO2 , _ZrO2 , _Ta2O5 , _Nb2O5 , _ZnS , _HfO , MoO, and CuO. Specifically, the photocurable resin is cured by light irradiation, and the photocurable resin is an acrylic photocurable resin such as a urethane acrylate photocurable resin, an epoxy acrylate photocurable resin, or a polyamide. A photo-curable resin, a polyimide-based photo-curable resin, a silicon-based photo-curable resin, an epoxy-based photo-curable resin, a polyester-based photo-curable resin, etc. may be included, but the types thereof are not limited.

According to one embodiment of the present invention, after applying a photocurable resin composition containing a photocurable resin containing a high refractive component onto a substrate, the photocurable resin composition is photocured, A grating layer can be formed on the substrate. Specifically, a photocurable resin composition containing an acrylic photocurable resin containing ZrO ₂ as high refractive particles is applied by a spin-coating method, and is photocurable at a temperature of about 80°C. After drying the resin composition for about 3 minutes, the photocurable resin composition may be photocured by irradiating ultraviolet rays having an intensity of 100 mW/cm ² or more at a temperature of about 40° C. for 60 seconds or more.

Further, the photocurable resin used to form the stress compensation layer is cured by light irradiation, and the photocurable resin is a urethane acrylate photocurable resin, an epoxy acrylate photocurable resin, or the like. acrylic photocurable resins, polyamide photocurable resins, polyimide photocurable resins, silicon photocurable resins, epoxy photocurable resins, polyester photocurable resins, etc. The type is not limited. _Further , the photocurable resin used to form the stress compensation layer includes _TiO2 , _{Al2O3 , Ga2O3} , _TeO2 , _ZrO2 , _{Ta2O5 , Nb2O5 ,} It may contain at least one high refractive component of ZnS, HfO, MoO, and CuO.

According to one embodiment of the present invention, the optical refractive index of each of the first substrate, the second substrate and the additional substrate may be 1.5 or more and less than 2.0. Substrates commonly used in the art can be included as long as the substrate maintains the optical refractive index within the range described above. Specifically, a glass containing a high refractive component, a resin film containing a high refractive component, or the like can be used as the substrate. The _high refractive component may include at _{least one} of _TiO2 , _{Al2O3 , Ga2O3} , _TeO2 , ZrO2, _Ta2O5 , _{Nb2O5 ,} and ZnS.

According to an embodiment of the present invention, the mold can be produced taking into account diffraction patterns contained in the first to third diffraction grating layers. Also, the mold can be produced in consideration of the antireflection pattern included in the stress compensation layer. As the mold, any mold used in the industry can be used without limitation. Specifically, metals and alloys such as nickel and nickel alloys, hard molds containing amorphous metals, or polyethylene terephthalate can be used. ) can be used. Also, the mold may be transparent.

According to one embodiment of the present invention, when imprinting is performed on the surface of the photocurable resin composition using a mold, there is a gap between the surface of the photocurable resin composition and the surface of the mold provided with the pattern. A mold provided with supports can be used to improve the contact of the . Specifically, the contact between the surface of the photocurable resin composition and the surface of the mold provided with the pattern is provided by providing a support on the other surface of the mold having a pattern engraved on one surface. Imprint efficiency can be increased by improving the quality. The support part may include a support layer made of polyethylene terephthalate (PET) or urethane material, an elastic layer provided on one side of the support layer, and an elastic layer containing PDMS (polydimethylsiloxane). does not limit the types of Also, the support layer and the elastic layer included in the support may be transparent, and the elastic layer of the support may be positioned on the other surface of the mold.

FIG. 12 is a schematic illustration of preparing a first diffractive substrate using two substrates according to one embodiment of the present invention. Specifically, in FIG. 12, after applying and drying the photocurable resin composition 700 on one surface of the first substrate 610 and one surface of the additional substrate 620, the other surface of the first substrate 610 and After facing the other surface of the additional substrate 620, a mold 810 having one surface engraved with a pattern provided on the first diffraction grating layer and one surface engraved with a pattern provided on the second diffraction grating layer. FIG. 8 schematically shows imprinting with a mold 820 having a thickness; Referring to FIG. 12, a support containing PET and PDMS and a support containing urethane and PDMS are provided on the other surfaces of molds 810 and 820 where no pattern is formed, and a photocurable resin composition is prepared. and the one side of the mold provided with the pattern can be improved. Similarly, a second diffractive substrate can be prepared using methods similar to those described above.

According to one embodiment of the present invention, the first to third diffraction grating layers and the stress compensation layer are each formed using a lithography process or a laser etching process. Specifically, after applying a photocurable resin composition on one surface of the first substrate and photocuring it, the surface of the cured product formed on one surface of the first substrate is subjected to a lithography process or laser etching. By forming a diffraction pattern using the process, a first diffraction grating layer can be formed on one surface of the first substrate. Similar to the method described above, a second grating layer, a third grating layer, and a stress compensation layer can be formed.

According to one embodiment of the present invention, the step of bonding the first diffractive substrate and the second diffractive substrate includes using spacers to ensure that the grating layer of the first diffractive substrate is aligned with the second diffractive substrate. It can be bonded so as to be spaced apart from the substrate. Specifically, spacers are provided between one end of the first diffraction base and one end of the second diffraction base, and the other end of the first diffraction base and the other end of the second diffraction base. can be connected via As the spacer, a known structure that can connect the first diffraction base material and the second diffraction base material can be used, and the spacer having elasticity may be used.

According to one embodiment of the present invention, the first diffraction base material and the first diffraction grating layer are separated from the third diffraction grating layer or the stress compensation layer while the first diffraction grating layer or the second diffraction grating layer is separated from the stress compensation layer. It can be combined with a bi-diffractive substrate. That is, the first diffraction grating layer or the second diffraction grating layer included in the first diffraction base does not contact the third diffraction grating layer or the stress compensation layer included in the second diffraction base. Thus, the first diffractive base and the second diffractive base can be coupled via spacers.

Another embodiment of the present invention provides a display unit including the diffractive light guide plate. The display unit can realize a provided image in Augmented Reality (AR), Mixed Reality (MR), or Virtual Reality (VR).

[Example]
EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples in order to specifically describe the present invention. Embodiments of the invention, however, may be modified in many different forms, and the scope of the invention should not be construed as limited to the embodiments set forth below. The examples herein are provided so that the invention will be more fully understood by those of ordinary skill in the art.

Example 1
Propylene glycol monomethyl ether acetate (PGMEA) as a solvent, ZrO ₂ as high refractive particles, dipentaerythritol hexaacrylate (DPHA) as a monomer, Irgacure 184 as a photoinitiator. A curable resin composition was prepared. As the first base material and the second base material, glass having a thickness of 0.8 mm and maintaining an optical refractive index of about 1.5 with respect to light with a wavelength of 400 nm or more and 700 nm or less was prepared.

The prepared photocurable resin composition was applied to one surface of the first substrate and dried at a temperature of about 80° C. for about 3 minutes. After that, the surface of the photocurable resin composition on the first substrate was imprinted using a mold in which a predetermined pattern of the first diffraction grating layer was engraved. In the process of imprinting, the photocurable resin composition is irradiated with ultraviolet rays having an intensity of about 100 mW/cm ² at a temperature of about 40° C. for about 60 seconds to photo-cure the first diffraction grating on one surface. A first substrate provided with a layer was produced. After that, the photocurable resin composition prepared on the other surface of the first substrate was applied and dried at a temperature of about 80° C. for about 3 minutes. After that, using a mold in which a predetermined pattern of the second diffraction grating layer was engraved, imprinting was performed on the surface of the photocurable resin composition on the first substrate. In the process of imprinting, the photocurable resin composition is irradiated with ultraviolet rays having an intensity of about 100 mW/cm ² at a temperature of about 40° C. for about 60 seconds to photo-cure the first diffraction grating on one surface. A first substrate provided with a layer and a second grating layer on the other side was prepared.

The prepared photocurable resin composition was applied to one surface of the second substrate and dried at a temperature of about 80° C. for about 3 minutes. Thereafter, using a mold in which a predetermined pattern of the third diffraction grating layer was engraved, imprinting was performed on the surface of the photocurable resin composition on the second substrate. In the process of imprinting, a third diffraction grating is formed on one surface by irradiating ultraviolet rays having an intensity of about 100 mW/cm ² at a temperature of about 40° C. for about 60 seconds to photo-cure the photo-curable resin composition. A second substrate provided with a layer was produced. After that, the photocurable resin composition prepared on the other surface of the second substrate was applied and dried at a temperature of about 80° C. for about 3 minutes. Thereafter, using a mold in which a preset antireflection pattern was engraved, imprinting was performed on the surface of the photocurable resin composition on the second substrate. In the process of imprinting, a third diffraction grating is formed on one surface by irradiating ultraviolet rays having an intensity of about 100 mW/cm ² at a temperature of about 40° C. for about 60 seconds to photo-cure the photo-curable resin composition. A second substrate was prepared which was provided with a layer and provided on the other side with a stress compensation layer comprising an antireflective pattern.

After that, after positioning the other surface of the first diffraction base and the other surface of the second diffraction base so as to face each other, one end of the first diffraction base and one end of the second diffraction base are The other end of the first diffractive base and the other end of the second diffractive base were connected by a spacer. Thus, a diffractive light guide plate including the first diffractive substrate and the second diffractive substrate was manufactured.

Example 2
A thiourethane film having a thickness of 0.8 mm and a refractive index of about 1.73 for light with a wavelength of 400 nm or more and 700 nm or less was prepared as the first base material and the second base material. A diffraction light guide plate was manufactured in the same manner as in Example 1 except for the above.

Analysis of Cross Sections of First and Second Diffraction Grating Layers Cross sections of the first and second diffraction grating layers produced in Example 1 were analyzed using an electron microscope (S-1400, Hitachi, Ltd.). did.

13A is a scanning electron microscope (SEM) photograph of the first grating layer according to Example 1 of the present invention, and FIG. 13B is a scanning electron microscope (SEM) photograph of the second grating layer according to Example 1 of the present invention. It is a photograph. Specifically, FIG. 13A (A) is a photograph of the first diffraction grating layer at a magnification of 5,000, and FIG. 13A (B) is a photograph of the first diffraction grating layer at a magnification of 15,000. 13A(C) is a photograph of the first diffraction grating layer taken at a magnification of 100,000. 13B(A) is a photograph of the second diffraction grating layer at a magnification of 5,000, and FIG. 13B(B) is a photograph of the second diffraction grating layer at a magnification of 15,000. FIG. 13B(C) is a photograph taken of the second diffraction grating layer at a magnification of 100,000.

13A and 13B, a method according to an embodiment of the present invention facilitates a diffractive light guide plate including a first diffractive substrate provided with a first grating layer and a second grating layer. You can confirm that it is manufacturable.

Morphological Analysis of Second Diffractive Substrate The morphologies of the third diffraction grating layer and the stress compensation layer produced in Example 1 were analyzed using an electron microscope (S-1400, Hitachi, Ltd.).

FIG. 14 is a scanning electron microscope (SEM) photograph of the third diffraction grating layer according to Example 1 of the present invention. Specifically, FIG. 14A is a photograph of the cross section of the third diffraction grating layer at a magnification of 5,000, and FIG. 14B is a photograph of the third diffraction grating layer at a magnification of 15,000. FIG. 14C is a photograph of the plane of the grating layer, and FIG. 14C is a photograph of the plane of the third grating layer at a magnification of 100,000.

Referring to FIG. 14, it can be confirmed that the second diffraction substrate including the third diffraction grating layer can be easily manufactured by the method according to one embodiment of the present invention.

FIG. 15 is a scanning electron microscope (SEM) photograph of the stress compensation layer including the antireflection pattern according to Example 1 of the present invention. Referring to FIG. 15, a moth-eye pattern of the antireflection pattern was formed on the stress compensation layer. Specifically, FIG. 15A is a photograph of the surface of the stress compensation layer including the moth-eye pattern at a magnification of 10,000, and FIG. 15B is a photograph of the moth-eye pattern at a magnification of 50,000. 15(C) is a photograph of the surface of the stress compensation layer including the pattern, and FIG. 15(C) is a photograph of the cross section of the stress compensation layer including the moth-eye pattern at a magnification of 10,000; FIG. 15(D). is a photograph of a cross section of a stress compensation layer including a moth-eye pattern taken at a magnification of 50,000.

Referring to FIG. 15, it can be confirmed that the second diffraction substrate provided with a stress compensation layer including a moth-eye pattern, which is an antireflection pattern, can be easily manufactured by a method according to an embodiment of the present invention. be able to.

Light transmittance analysis reference example 1 of the second diffraction base material
A glass substrate having a thickness of 0.8 mm and having a refractive index of about 1.5 for light with a wavelength of 400 nm or more and 700 nm or less was prepared.

Reference example 2
The same substrate as in Reference Example 1 was prepared, and the same photocurable resin composition as in Example 1 was prepared. After that, the photocurable resin composition was applied on one side of the substrate and dried at a temperature of about 80° C. for about 3 minutes. Thereafter, ultraviolet rays having an intensity of about 100 mW/cm ² are irradiated for about 60 seconds at a temperature of about 40° C. to cure the photocurable resin composition, thereby producing a substrate having a resin layer formed on one surface. did.

Reference example 3
The same substrate as in Reference Example 1 was prepared, and the same photocurable resin composition as in Example 1 was prepared. After that, the photocurable resin composition was applied on one side of the substrate and dried at a temperature of about 80° C. for about 3 minutes. After that, using a mold in which a predetermined antireflection pattern was engraved, imprinting was performed on the surface of the photocurable resin composition applied on one side of the substrate. In the process of imprinting, the photocurable resin composition is cured by irradiating ultraviolet rays having an intensity of about 100 mW/cm ² at a temperature of about 40° C. for about 60 seconds to form a resin layer including an antireflection pattern. A base material was produced.

Reference example 4
The same substrate as in Reference Example 1 was prepared, and the same photocurable resin composition as in Example 1 was prepared. After that, the photocurable resin composition was applied on one side of the substrate and dried at a temperature of about 80° C. for about 3 minutes. Thereafter, using a mold in which a predetermined pattern of the third diffraction grating layer was engraved, imprinting was performed on the surface of the photocurable resin composition applied on the substrate. In the process of imprinting, the photocurable resin composition is photocured by irradiating ultraviolet rays having an intensity of about 100mW/cm ² at a temperature of about 40°C for about 60 seconds to form a third diffraction grating layer on one surface. A formed substrate was produced.

Reference example 5
The same substrate as in Reference Example 1 was prepared, and the same photocurable resin composition as in Example 1 was prepared. After that, the photocurable resin composition was applied on one side of the substrate and dried at a temperature of about 80° C. for about 3 minutes. After that, using a mold in which a predetermined pattern of the third diffraction grating layer was engraved, imprinting was performed on the surface of the photocurable resin composition applied on the substrate. In the process of imprinting, the photo-curable resin composition was photo-cured by irradiating UV rays having an intensity of about 100 mW/cm ² at a temperature of about 40° C. for about 60 seconds. After that, the photocurable resin composition was applied to the other surface of the substrate and dried at a temperature of about 80° C. for about 3 minutes. After that, the photocurable resin composition is photocured by irradiating ultraviolet rays having an intensity of about 100mW/cm ² at a temperature of about 40°C for about 60 seconds to form a third diffraction grating layer on one side and a third diffraction grating layer on the other side. A substrate having a resin layer formed thereon was manufactured.

Reference example 6
A thiourethane-based film having a thickness of 0.8 mm and having a refractive index of about 1.73 for light with a wavelength of 400 nm to 700 nm was prepared.

Reference example 7
The same substrate as in Reference Example 6 was prepared, and the same photocurable resin composition as in Example 1 was prepared. Thereafter, using a mold in which a predetermined pattern of the third diffraction grating layer was engraved, imprinting was performed on the surface of the photocurable resin composition applied on the substrate. In the process of imprinting, the photocurable resin composition is photocured by irradiating ultraviolet rays having an intensity of about 100mW/cm ² at a temperature of about 40°C for about 60 seconds to form a third diffraction grating layer on one surface. A formed substrate was produced.

FIG. 16 is a graph showing the results of measuring the light transmittance of the second diffractive substrate prepared in Example 1 of the present invention and the substrates prepared in Reference Examples 1 to 5. FIG. Specifically, a light source (JIS K7136) having a wavelength of 380 nm or more and 1200 nm or less was irradiated onto the second diffractive substrate prepared in Example 1 and the substrates prepared in Reference Examples 1 to 5. , and the results of measuring the light transmittance using a light transmittance measuring apparatus HM-150 are shown in FIG.

Referring to FIG. 16, the second diffractive substrate including the third diffraction grating layer and the stress compensation layer prepared in Example 1 of the present invention has a wavelength of about 700 nm or more and 1200 nm or less. It can be confirmed that the light transmittance is superior to that of the substrates prepared in Examples 1 to 5.

FIG. 17 is a graph showing the results of measuring the light transmittance of the second diffractive substrate prepared in Example 2 of the present invention and the substrates prepared in Reference Examples 6 and 7. FIG. Specifically, a light source (JIS K7136) having a wavelength of 380 nm or more and 1200 nm or less was irradiated onto the second diffractive substrate prepared in Example 2 and the substrates prepared in Reference Examples 6 and 7. , and the results of measuring the light transmittance using a light transmittance measuring apparatus HM-150 are shown in FIG.

Referring to FIG. 17, the second diffractive substrate including the third diffraction grating layer and the stress compensation layer prepared in Example 2 of the present invention has a wavelength of about 700 nm or more and 1200 nm or less. 6 and Reference Example 7, it can be confirmed that the light transmittance is superior to that of the base material prepared in Reference Example 7.

Deflection analysis reference example 8 of the second diffraction base material
A thiourethane film having a thickness of 0.8 mm and having a refractive index of about 1.73 for light with a wavelength of 400 nm to 700 nm was prepared.

After that, the thiourethane film was left at a temperature of 80° C. for about 3 minutes (drying step). After that, ultraviolet rays having an intensity of about 100 mW/cm ² were irradiated for about 60 seconds at a temperature of about 40° C. (UV irradiation step).

Reference example 9
The same substrate as in Reference Example 8 was prepared, and the same photocurable resin composition as in Example 1 was prepared. After that, the photocurable resin composition was applied onto one surface of the substrate (application step). After that, the substrate coated with the photocurable resin was dried at a temperature of about 80° C. for about 3 minutes (drying step). After that, using a mold in which a predetermined antireflection pattern was engraved, imprinting was performed on the surface of the photocurable resin composition applied on one side of the substrate. In the process of imprinting, the photocurable resin composition is cured by irradiating ultraviolet rays having an intensity of about 100 mW/cm ² at a temperature of about 40° C. for about 60 seconds (UV irradiation step) to form an antireflection pattern. A substrate having a stress compensation layer formed on one surface was produced.

Deformation of the substrate during the manufacturing process of the substrates in Reference Examples 8 and 9 was photographed as 3D images using a 3D-coordinated measuring mechanism (3D-CMM).

18A is a diagram showing a 3D image of the base material in the process of manufacturing the base material in Reference Example 8, and FIG. 18B is a diagram showing a 3D image of the base material in the process of manufacturing the base material in Reference Example 9. be. Specifically, FIG. 18A shows 3D images of the morphology of the substrate prepared in Reference Example 8, the morphology of the substrate subjected to the drying step, and the morphology of the substrate subjected to the UV irradiation step. Indicated. Further, FIG. 18B shows the morphology of the substrate prepared in Reference Example 9, the morphology of the substrate subjected to the coating step, the morphology of the substrate subjected to the drying step, and the morphology of the substrate subjected to the UV irradiation step. A 3D image is shown.

Referring to FIG. 18A, in Reference Example 8, when performing the drying step and the UV irradiation step having the same conditions as the process of manufacturing the diffraction substrate according to one embodiment of the present invention, the substrate is deformed. can be confirmed. On the other hand, referring to FIG. 18B, in the case of Reference Example 9, by forming a stress prevention layer on one surface of the substrate, the substrate is not deformed even when the drying step and the UV irradiation step are performed. can be confirmed to be suppressed.

Therefore, by forming the stress compensating layer on the other side of the second diffraction base having the third diffraction grating layer formed on one side, the second diffraction base is formed during the manufacturing process of the second diffraction base. It can be predicted that deformation can be suppressed. In addition, by forming the second diffraction grating layer on the other surface of the first diffraction base on which the first diffraction grating layer is formed on one surface, the first diffraction base is formed during the manufacturing process of the first diffraction base. It can also be expected to suppress the material from deforming.

10: Base material layer 11: First base material layer 12: Second base material layer 13: Third base material layer 20: Pattern layer 21: First pattern layer 22: Second pattern layer 23: Third pattern layer 100: First diffraction base material 200: Second diffraction base material 310: First diffraction grating layer 320: Second diffraction grating layer 330: Third diffraction grating layer 311, 321, 331: First diffraction pattern 312, 322, 332, 332 ': Second diffraction pattern 313, 323, 333: Third diffraction pattern 400: Spacer 511, 521, 531: First region 512, 522, 532, 532': Second region 513, 523, 533: Third region 610 : First substrate 620: Additional substrate 700: Photocurable resin composition 810, 820: Mold 900: Stress compensation layer

Claims (15)

comprising a first diffractive substrate and a second diffractive substrate provided on the first diffractive substrate;
the first diffractive substrate includes a first diffractive grating layer on one side and a second diffractive grating layer on the other side;
said second diffractive substrate comprising a third grating layer on one side and a stress compensation layer on the other side;
The first diffraction grating layer separates light with a wavelength of 550 nm or more and 700 nm or less,
The second diffraction grating layer separates light with a wavelength of 400 nm or more and 550 nm or less,
The third diffraction grating layer separates light with a wavelength of 450 nm or more and 650 nm or less,
the stress compensation layer has a stress in the same direction as the stress of the third grating layer ;
Each of the first to third diffraction grating layers has a first region where light is incident, a second region where the incident light is diffused and moved, and a third region where the moved light is extracted. including
A first diffraction pattern is included in the first regions of the first diffraction grating layer, the second diffraction grating layer and the third diffraction grating layer, and a second diffraction pattern is included in the first diffraction grating layer and the second diffraction grating layer. contained in the second region of the grating layer and the third grating layer, and a third diffraction pattern in the third region of the first grating layer, the second grating layer and the third grating layer is included and
The diffraction light guide plate , wherein the first diffraction pattern, the second diffraction pattern and the third diffraction pattern included in the first diffraction grating layer have different forms . 2. The diffractive light guide plate of claim 1, wherein the stress compensation layer includes an antireflection pattern. 3. The diffractive light guide plate according to claim 1, wherein each of said first diffractive base material and said second diffractive base material has a thickness of 0.1 mm or more and 2 mm or less. The diffractive light guide plate according to any one of claims 1 to 3, wherein the diffraction grating layer of the first diffractive base is separated from the second diffractive base. The first regions are included in positions corresponding to each other in a direction perpendicular to the surface of the first diffraction base or the second diffraction base in each of the first diffraction grating layer to the third diffraction grating layer. ,
the third region is included in each of the first diffraction grating layer to the third diffraction grating layer at positions corresponding to each other in a direction perpendicular to the surface of the first diffraction substrate or the second diffraction substrate ; The diffractive light guide plate according to any one of claims 1 to 4. 6. The diffractive light guide plate of claim 5, wherein the third region of the first to third diffraction grating layers has a refractive index that gradually increases from one side to the other side. 6. The diffractive light guide plate of claim 5, wherein the third region comprises a diffractive pattern including slanted pattern structures whose heights gradually increase from one side to the other side. 6. The diffractive light guide plate of claim 5, wherein the third region includes a diffraction pattern including a pattern structure whose duty increases gradually from one side to the other side. providing a first diffractive substrate comprising a first grating layer on one side and a second grating layer on the other side;
providing a second diffractive substrate comprising a third grating layer on one side and a stress compensation layer on the other side;
The method of manufacturing a diffractive light guide plate according to claim 1, comprising bonding the first diffractive substrate and the second diffractive substrate. The step of preparing the first diffraction substrate includes forming the first diffraction grating layer on one surface of the first substrate and forming the second diffraction grating layer on the other surface of the first substrate. 10. The method of manufacturing a diffractive light guide plate according to claim 9, wherein the first diffractive substrate is manufactured. The step of preparing the second diffraction substrate includes forming the third diffraction grating layer on one surface of the second substrate, forming the stress compensation layer on the other surface of the second substrate, and 11. The method of manufacturing a diffractive light guide plate according to claim 9 or 10, wherein the second diffractive base material is manufactured. 12. The method of manufacturing a diffractive light guide plate according to claim 9, wherein the step of preparing the second diffractive substrate forms an antireflection pattern on the stress compensation layer. 13. The diffraction according to claim 12, wherein the first to third diffraction grating layers and the stress compensation layer are each formed using an imprinting process using a photocurable resin composition and an imprint mold. A method for manufacturing a light guide plate. 13. The method of manufacturing a diffraction light guide plate according to claim 12, wherein said first to third diffraction grating layers and said stress compensation layer are each formed using a lithography process or a laser etching process. The step of bonding the first diffraction substrate and the second diffraction substrate uses a spacer to bond the diffraction grating layer of the first diffraction substrate and the second diffraction substrate apart from each other. 15. The method of manufacturing a diffractive light guide plate according to any one of claims 9 to 14.

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